Makita 6906 Owners Manual - Page 7

The fastening torque is affected by a wide variety of factors including the following. After fastening, always check the torque with a torque wrench. 1. Voltage Voltage drop will cause a reduction in the fastening torque. 2. Socket • Failure to use the correct size socket will cause a reduction in the fastening torque. • A worn socket ( wear on the hex end or square end ) will cause a reduction in the fastening torque. 3. Bolt • Even though the torque coefficient and the class of bolt are the same, the proper fastening torque will differ according to the diameter of bolt. • Even though the diameters of bolts are the same, the proper fastening torque will differ according to the torque coefficient, the class of bolt and the bolt length. 4. The use of the universal joint or the extension bar somewhat reduces the fastening force of the impact wrench. Compensate by fastening for a longer period of time. 5. The manner of holding the tool or the material of driving position to be fastened will affect the torque. MAINTENANCE CAUTION: • Always be sure that the tool is switched off and unplugged before attempting to perform inspection or maintenance. 1. Limit mark 001145 Replacing carbon brushes Remove and check the carbon brushes regularly. Replace when they wear down to the limit mark. Keep the carbon brushes clean and free to slip in the holders. Both carbon brushes should be replaced at the same time. Use only identical carbon brushes. 1 7